Liquid container and double container

ABSTRACT

A ring-like reinforcement part  2  is secured to an upper end face of a bottomed cylindrical container main body  1.  The container main body  1  is formed of a flexible film-like member which is composed of polyethylene, polypropylene or the like. The reinforcement part  2  has strength enough to prevent the container main body  1  from greatly deformed and to prevent liquid, such as adhesive agent, coating material or the like stored in the container main body  1  from overflowing when the container main body  1  is lifted up through the reinforcement part  2.

BACKGROUND OF THE INVENTION

This invention relates to a liquid container suited for storing an adhesive agent, a coating material and the like, and a double container using the liquid container as its inner container.

In general, a metal-made pail, a metal-made drum, and a bucket formed of a hard plastic are used in case a necessity arises for storing an adhesive agent, a coating material or the like. However, since those containers are high in strength, waste disposal for those containers is difficult.

Recently, there has been often used a double container, as a container for storing adhesive agent or the like, as described in U.S. Pat. No. 5,727,878. The double container comprises an outer container and an inner container. The outer container is formed in a bottomed cylindrical shape having a bottom part at its lower end part and an opening at its upper end. The outer container is formed of metal or plastic with a predetermined strength so that it can retain a constant shape. On the other hand, the inner container is likewise formed in a bottomed cylindrical shape as in the outer container but it is formed of a thin film-like member having flexibility which is composed of synthetic resin. An inverted U-shaped engagement part is formed on an upper end part of the inner container. The inner container inserted into the outer container through the upper end opening part until its engagement part is engaged with the upper end part of the outer container.

In the double container thus constructed, an adhesive agent or the like is stored in the inner container. Therefore, when the adhesive agent or the like is used up, only the inner container may be subjected to waste disposal. Since the inner container is composed of a thin film-like member having flexibility, it can be crushed into a reduced size. Therefore, it can easily be subjected to waste disposal.

Since the inner container used for the double container is entirely composed of a film-like member having flexibility, it has the above-mentioned advantage but is has such a disadvantage that the inner container hardly has a shape retainability for retaining its own shape constant. Thus, it is encountered with such a problem that the inner container storing adhesive agent, etc. cannot be used alone at all. For example, it is practically impossible that the inner container is removed from the outer container and shifted into other outer container.

Moreover, when coating material or adhesive agent having a high viscosity is agitated, the inner container is twisted by viscous resistance of the coating material or the like. Then, since the inner container is slightly reduced in height, the engagement part is disengaged from an upper end of the outer container. Furthermore, in case the height of the inner container is smaller than the depth of the outer container and the bottom part of the inner container is separated upward from the bottom part of the outer container, the engagement part is disengaged from the upper end part of the outer container by weight of the adhesive agent or the like stored in the inner container and the inner container is brought into the outer container. Therefore, in case there are various types of outer containers having different heights, it is necessary to prepare various types of inner containers which are in match with the various outer containers having different heights, thus resulting in high manufacturing costs and high maintenance fees.

SUMMARY OF THE INVENTION

In order to solve the above problems, a liquid container according to the present invention comprises a bottomed cylindrical container main body having a bottom part at a lower end part thereof and opening at an upper end thereof, and an annular reinforcement part disposed at an upper end part of the container main body, the container main body being entirely formed of a flexible thin film-like member, and the reinforcement part having strength enough to retain a constant shape in section.

It is preferable that the container main body and the reinforcement part are formed of a resin, and the reinforcement part is fused to an upper end part of the container main body.

The reinforcement part preferably has a protrusion formed on an outer peripheral surface thereof and protruding radially outward with respect to an outer periphery of the container main body. The protrusion is preferably annularly formed on the reinforcement part over an entire periphery thereof and the protrusion is preferably disposed at an upper end part of an outer peripheral surface of the reinforcement member.

In order to solve the above problems, a double container according to the present invention comprises a cylindrical outer container which is open at least at an upper end part thereof, and a bottomed cylindrical inner container having a bottom part at a lower end part thereof and opening at an upper end thereof, the inner container including a bottomed cylindrical container main body having a bottom part at a lower end part thereof and opening at an upper end thereof, and an annular reinforcement part disposed at an upper end part of the container main body, the container main body being entirely formed of a flexible thin film-like member, the reinforcement part having strength enough to retain a constant shape in section, and the reinforcement part having a protrusion formed on an outer peripheral surface thereof and protruding radially outward with respect to an outer periphery of the container main body, the inner container being inserted into the outer container through the upper end opening part of the outer container, and the protrusion being placed on an upper end face of the outer container.

It is preferable that the container main body and the reinforcement part are formed of a resin, and the reinforcement part is fused to an upper end part of the container main body.

The reinforcement part preferably has a protrusion formed on an outer peripheral surface thereof and protruding radially outward with respect to an outer periphery of the container main body, and the protrusion is preferably annularly formed on the reinforcement part over an entire periphery thereof. Moreover, the protrusion is preferably disposed on an upper end part of an outer peripheral surface of the reinforcement part.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1(A) is a plan view showing a first embodiment of a liquid container according to the present invention.

FIG. 1(B) is a sectional view taken on line X-X of FIG. 1(A).

FIG. 1(C) is a view when viewed in a direction as indicated by an arrow Y of FIG. 1(A).

FIG. 2(A) is a plan view showing a second embodiment of a liquid container according to the present invention.

FIG. 2(B) is a sectional view taken on line X-X of FIG. 2(A).

FIG. 2(C) is a view when viewed in a direction as indicated by an arrow Y of FIG. 2(A).

FIG. 3(A) is a plan view showing a third embodiment of a liquid container according to the present invention.

FIG. 3(B) is a sectional view taken on line X-X of FIG. 3(A).

FIG. 3(C) is a view when viewed in a direction as indicated by an arrow Y of FIG. 3(A).

FIG. 4(A) is a plan view showing a fourth embodiment of a liquid container according to the present invention.

FIG. 4(B) is a sectional view taken on line X-X of FIG. 4(A).

FIG. 4(C) is a view when viewed in a direction as indicated by an arrow Y of FIG. 4(A).

FIG. 5(A) is a front view showing a fifth embodiment of a liquid container according to the present invention.

FIG. 5(B) is a side view of the above.

FIG. 6 is a plan view, partly omitted, showing a handle used in the embodiment shown in FIG. 5.

FIG. 7(A) is a front view showing a sixth embodiment of a liquid container according to the present invention.

FIG. 7(B) is a side view of the above.

FIG. 8(A) is a front view showing a handle used in the embodiment shown in FIG. 7.

FIG. 8(B) is a side view of the above.

FIG. 9(A) is a sectional view showing a first embodiment of a double container according to the present invention, showing a state in which the operation for inserting an inner container into an outer container is undergoing.

FIG. 9(B) is likewise a sectional view of the above, but showing another state in which the inserting operation is finished.

FIG. 10(A) is a sectional view showing a second embodiment of a double container according to the present invention, showing a state in which the operation for inserting an inner container into an outer container is undergoing.

FIG. 10(B) is likewise a sectional view of the above, but showing another state in which the inserting operation is finished.

FIG. 11 is a view when viewed in a direction as indicated by an arrow X of FIG. 10(B).

FIG. 12 is a plan view showing a third embodiment of a double container according to the present invention.

FIG. 13(A) is a view showing a fourth embodiment of a double container according to the present invention, showing a state before inserting an inner container into an outer container.

FIG. 13(B) is a sectional view of the above, but showing another state in which the inserting operation is finished.

FIG. 14 is a sectional view taken on line X-X of FIG. 13(B).

FIG. 15 is a view when viewed in a direction as indicated by an arrow X of FIG. 14.

FIG. 16 is a plan view showing a fifth embodiment of a double container according to the present invention.

FIG. 17(A) is a sectional view showing a sixth embodiment of a double container according to the present invention, showing a stage in which the operation for inserting an inner container into an outer container is undergoing.

FIG. 17(B) is likewise a sectional view of the above, but showing another state in which the inserting operation is finished.

FIG. 17(C) is a view when viewed in a direction as indicated by an arrow X of FIG. 17(B).

FIG. 18(A) is a view showing a seventh embodiment of a double container according to the present invention, showing one state before inserting an inner container into an outer container.

FIG. 18(B) is a sectional view of the above, but showing another state in which the inserting operation is finished.

FIG. 18(C) is a view when viewed in a direction as indicated by an arrow X of FIG. 18(B).

FIG. 18(D) is a sectional view taken on line Y-Y of FIG. 18(C).

DETAILED DESCRIPTION OF THE EMBODIMENTS

The best mode for carrying out the present invention will be described hereinafter with reference to the drawings.

FIG. 1 shows a first embodiment of a liquid container according to the present invention. A liquid container A according to this embodiment comprises a container main body 1 and a reinforcement part 2 which are mutually secured.

The container main body 1 is composed of a film-like member having flexibility and comprises a cylindrical part 11 having a circular shape in section with its axis directing vertically and a bottom part 12 integrally disposed at a lower end part of this cylindrical part 11 and adapted to close a lower end part of the cylindrical part 11. One example of the film-like member composing the container main body 1 includes a thin film composed of resin such as, for example, polyethylene, polypropylene or the like. The thickness of the film-like member may optionally be selected from the range which satisfies the condition capable of easily crushing the container main body 1. It is preferable, however, that the thickness of the film-like member is large enough for the container main body 1 to retain generally its constant shape when the container A is placed on a flat floor or the like with the container main body 1 located under and with the reinforcement part 2 located above in case the container A is in an empty state with no adhesive agent or the like stored therein. From that view point, the thickness of the film-like member composing the container main body 1 is set to, for example, 300 to 1000 μm.

The reinforcement part 2 is composed of resin such as hard polyethylene, polypropylene or the like so that it can have a predetermined strength. The reinforcement part 2 is formed in a circular annular shape in a plan view. The strength of the reinforcement part 2 is set such that the reinforcement part 2 can not only retain its own shape constant but also the shape of the container body 1 even when the container main body 1 storing therein adhesive agent, coating material or the like is placed on a flat floor or the like or even when the container main body 1 is horizontally lifted up through the reinforcement part 2. The inside diameter of the reinforcement part 2 may be set smaller than the inside diameter of the container main body 1. It is preferable, however, that the inside diameter of the reinforcement part 2 is set to be generally equal to the inside diameter of the container main body 1 (cylindrical part 11) as in this embodiment. The outside diameter of the reinforcement part 2 is extensively larger than the outside diameter of the container main body 1 so that the thickness of the reinforcement part 2 is increased, and shape retainability of the reinforcement part 2 is equal to or more than a predetermined level. An annular flange part (protrusion) 21 projecting radially outward from an outer peripheral surface of the reinforcement part 2 is integrally formed on an upper end part of the reinforcement part 2. A pair of grip parts 22, 22 are integrally formed on the flange part 21. The pair of grip parts 22, 22 are arranged in such a manner as to be away by 180 degrees from each other in the peripheral direction of the flange part 21.

A lower surface of the reinforcement part 2 is secured to an upper surface of the container main body 1 by suitable means such as bonding, fusing or the like. The container main body 1 and the reinforcement part 2 are secured to each other and aligned to each other in axis. Therefore, an inner peripheral surface of the reinforcement part 2 forms a same circular cylindrical surface together with an inner peripheral surface of the container main body 1. On the other hand, an outer peripheral surface of the reinforcement part 2 is protruded radially outward from an outer peripheral surface of the container main body 1. Particularly, the flange part 21 is greatly protruded from the outer peripheral surface of the container main body 1.

The container A thus constructed can be manufactured in the manner as mentioned hereinafter, for example. That is, the container main body 1 can be molded by cavity forming or the like, and the reinforcement part 2 can be molded by extrusion molding. The container main body 1 is preliminarily molded before the reinforcement part 2 is molded. At the time of molding of the reinforcement part 2, the container main body 1 is arranged such that the upper end face of the container main body 1 contacts an inner surface of the cavity for molding the lower end face of the reinforcement part 2. When a molten resin for molding the reinforcement part 2 is filled in the cavity in that condition, the upper end part of the container main body 1 is melted. Thereafter, when the resin filled in the cavity is hardened to mold the reinforcement part 2, the upper end part of the container main body 1 is fused to the lower surface of the reinforcement part 1. In case the container main body 1 and the reinforcement part 2 are fused together in the manner as mentioned above, the resin composing the container main body 1 is preferably selected from the same type as the resin composing the reinforcement part 2 so that easy and reliable fusing can be obtained.

In the liquid container A constructed in the manner as mentioned above, the container A can be reduced in capacity by press-crushing the container main body 1 in its axial direction. Therefore, the container A can easily be subjected to waste disposal. Since the reinforcement part 2 retains the shape of the container main body 1, particularly, the cylindrical part 11 so that the cylindrical part 11 is prevented from deforming heavily, the container main body 1 is not greatly deformed even if the container A storing therein adhesive agent or the like is placed on a horizontal floor surface or the like, or lifted up through the grip part 22. Therefore, the container A can be used alone. Moreover, since the reinforcement part 2 has a sufficient strength and shape retainability, a cap member can be fitted, either internally or externally, to the upper end opening part or upper end outer peripheral part (outer peripheral part of the flange part 21 in this embodiment) of the reinforcement part 2. By this, the upper end opening part of the container A can be tightly closed.

Other embodiments of the present invention will now be described. In the embodiments to be described hereinafter, only the construction which is different from the above embodiment is described, and identical components are denoted by identical reference numerals and description thereof are omitted.

FIG. 2 shows a second embodiment of a liquid container according to the present invention. In a liquid container B of this embodiment, a cylindrical part 11 of a container main body 1 is formed in a regular square shape in section, and a bottom part 12 of the container main body 1 and a reinforcement part 2 are each formed in a regular square shape in section corresponding to the shape of the cylindrical part 11.

FIG. 3 shows a third embodiment of a liquid container according to the present invention. In a liquid container C of this embodiment, a pair of engagement parts 23, 23 are formed instead of the pair of grip parts 22, 22. The engagement part 23 is formed on an outer peripheral surface of the reinforcement part 2 at the lower side of the flange part 21. The engagement part 23 comprises a shaft part 23 a protruding radially outward from the outer peripheral surface of the reinforcement part 2, and a head part 23 b formed on a front end part of the shaft part 23 a and having a larger diameter than the shaft part 23 a. The pair of engagement parts 23, 23 are arranged on the reinforcement part 2 in such a manner as to be away by 180 degrees from each other in the peripheral direction of the reinforcement part 2. Moreover, the pair of engagement parts 23, 23 are arranged such that their axes are passed through the center of the reinforcement part 2 and aligned with each other. A flat part 21 a is formed on each of those parts of the flange part 21 opposing the engagement parts 23, 23. Owing to this arrangement, the front end part of the shaft part 23 a is allowed to protrude radially outward from an outer peripheral surface (flat part 21 a) of the flange part 21.

FIG. 4 shows a fourth embodiment of a liquid container according to the present invention. A liquid container D of this embodiment is a modification of the above-mentioned liquid container C. In this liquid container D, a container main body 1 and a reinforcement part 2 are each formed in a regular square shape in section. Engagement parts 23, 23 are respectively arranged at central parts of opposing two sides of all the four sides of the reinforcement part 2. A front end part and a head part 23 b of the shaft parts 23 a of each engagement part 23 are allowed to protrude radially outward from an outer peripheral surface of the flange part 21.

FIG. 5 shows a fifth embodiment of a liquid container according to the present invention. A liquid container E of this embodiment is the above-mentioned container C but with a handle 3 additionally applied thereto. The handle 3 is composed of a relatively flexible resin. As shown in FIG. 6, the handle 3 is formed in a belt-like shape. The length of the handle 3 is longer than the outside diameter of a flange part 21 of a reinforcement part 2. Two pairs of circular holes 31, 31 are formed, one pair each, on opposite end parts of the handle 3. The circular holes 31, 31 forming the pair is arranged away from each other in the longitudinal direction of the handle 3. Each circular hole 31 has the inside diameter generally equal to the outside diameter of a shaft part 23 a of an engagement part 23. A slit 32 whose opposite end parts are in communication with the circular hole 31 is formed between the circular holes 31, 31. The width of the slit 32 in its natural state (width of the slit 32 with no external force acting thereon the end parts of the handle 3) is smaller than the outside diameter of the shaft part 23 a. However, since the slit 32 is such dimensioned that the opposite end parts of the handle 3 are deformed to enlarge the width of the slit 32 so that a head part 23 b of the engagement part 23 is allowed to pass through the inside of the slit 32. Therefore, by allowing the head part 23 b to pass through the slit 32, the shaft part 23 a can penetrate through the slit 32. By moving the handle 3 toward the central part side from the opposite end part sides in that condition, the shaft part 23 a can be fitted into the circular hole 31 which is located at the end part side of all the two circular holes 31, 31. By fitting the circular holes 31, 31 formed in the opposite end parts of the handle 3 in the manner as just mentioned to the shaft parts 23 a, 23 a, respectively, the handle 3 is attached to the container C in its inverted U-shape as shown in FIG. 5(A).

In the container E thus constructed, by gripping the handle 3, the container E can easily be carried. Moreover, since the shaft part 23 a is turnably fitted to the circular hole 31, at that time of taking out the adhesive agent, or the like stored in the container E, the adhesive agent or the like can easily be taken out by slanting the handle 5 in such a manner as indicated by an imaginary line of FIG. 5(B). If the handle 3 is preliminarily turned until its central part in the longitudinal direction is abutted with the outer peripheral surface of the container main body 1, the adhesive agent or the like can more easily be taken out.

FIG. 7 shows a sixth embodiment of a liquid container according to the present invention. A liquid container F of this embodiment is the above-mentioned container C but with a handle 4 additionally applied thereto. The handle 4 is composed of a rod which is made of steel. As shown in FIG. 8, the handle 4 is formed in an inverted U-shape. A hook part 41 is formed on each of the opposite end parts of the handle 4. This hook part 41 has a generally ¾ arcuate shape, and the remaining generally ¼ arcuate part of the hook part 41 is open. The shaft part 23 a can be inserted into the hook part 41 through the opening part by elastically deforming the hook part 41 and spreading the opening part. By inserting the shaft parts 23 a, 23 a into the two hook parts 41, 41, respectively, the container F can be hand-carried through the handle 4. Moreover, since the inside diameter of the hook part 41 is set to be generally equal to the outside diameter of the shaft part 23 a and the shaft part 23 a is turnably inserted in the hook part 41, the handle 4 can be turned about the shaft parts 23 a, 23 a as in the case with the handle 3 in the container E of the above-mentioned embodiment.

FIG. 9 shows a first embodiment of a double container according to the present invention. A double container G of this embodiment includes an outer container 5, and the above-mentioned container A as an inner container inserted in the outer container 5. The outer container 5 is composed of a metal plate. The outer container 5 includes an outer cylindrical part 51 having a circular shape in section with its axis directing vertically and a bottom part 52 disposed at a lower end part of the outer cylindrical part 51. The outer cylindrical part 51 has a constant inside diameter. The inside diameter of the outer cylindrical part 61 is set to be generally equal to the outside diameter of a reinforcement part 2 (outside diameter of the reinforcement part 2 at the lower side of the flange part 21). The depth of the outer cylindrical part 51 is set to be slightly larger than the distance between a lower surface of the flange part 21 and a lower surface of the container main body 1 of the container A. An annular support part 51 a horizontally protruding radially outward is formed on an upper end part of the outer cylindrical part 51. The outside diameter of this annular support part 51 a is set to be generally equal to the outside diameter of the flange part 21.

The container A as the inner container is inserted in the outer container 5 through its upper end opening part. A part of the reinforcement part 2 at a lower side of the flange part 21 is removably fitted an upper end inner peripheral surface of an outer tube 5, and the flange part 21 is placed on the annular support part 51 a over its entire periphery. A liquid such as adhesive agent, coating material or the like is stored in the container A.

In the double container G thus constructed, when the adhesive agent or the like stored in the container A is used up, only the container A may be subjected to waste disposal. Therefore, the container A may easily be subjected to waste disposal as mentioned above. Moreover, since the container A can be handled alone, the container A can be taken out of the outer container 5 and shifted into other outer container, for example. At that time, since the flange parts 22, 22 of the container A are protruded radially outward from the annular support part 51 a of the outer container 5, shifting of the container A can easily be performed by holding the flange parts 22, 22 with hands. Moreover, since the reinforcement part 2 having rigidity is supported by the annular support part 51 a, the entire container A is never brought into the outer container 5 even if the cylindrical part 11 of the container A is twisted at the time of agitating the adhesive agent or the like. For the same reason, even in case the depth of the outer container 5 is larger than the height of the container A and the bottom part 12 of the container A with the adhesive agent or the like stored therein does not contact the bottom part 52 of the outer container 5, the entire container A can be prevented from being brought into the outer container 5. Therefore, it is no more required to prepare various kinds of containers A having different heights, and the manufacturing costs and maintenance fees can be reduced to that extent.

FIGS. 10 and 11 show a second embodiment of a double container according to the present invention. In a double container H of this embodiment, an outer container 5A is used instead of the outer container 5 of the above-mentioned double container G. The outer container 5A is composed of a corrugate board. The depth of the outer container 5A is set to be generally equal to or slightly smaller than the distance between a lower surface of the flange part 21 and a lower surface of the bottom part 12 of the container A. Of course, the depth of the outer container 5A may be set to be larger than the above-mentioned distance. The outer cylindrical part 51 of the outer container 5 is formed in a regular square shape in section. The bottom part 52 is also formed in a regular square shape corresponding to the shape of the outer cylindrical part 51. The interval (internal dimension) between opposing two sides of the outer cylindrical part 51 is set to be generally equal to the outside diameter of a cylindrical part 11 of the container A. The external dimension of opposing two sides of the outer cylindrical part 51 is set to be slightly smaller than the outside diameter of the flange part 22.

The container A as an inner container is inserted in the outer container 5A through its upper end opening part. In that condition, a part of a reinforcement part 2 at a lower side of the flange part 21 is contacted with the central part of the inner peripheral surface of each of four sides of the outer container 5A, and the flange part 21 is placed on the central part of the upper surface of each of four sides of the outer container 5A. All the remaining construction of the double container H is same as the above-mentioned double container G and description thereof is omitted.

FIG. 12 shows a third embodiment of a double container according to the present invention. A double container I of this embodiment is a modification of the double container H. In this double container I, a container B instead of the container A is used as an inner container. A part of the container B at a lower side of the flange part 21 of the reinforcement part 2 is tightly fitted to an upper end part of the outer container 5A with almost no gap left therebetween.

FIGS. 13 through 15 show a fourth embodiment of a double container according to the present invention. In a double container J of this embodiment, an outer container 5B is used instead of the outer container 5A, and a container C is used as an inner container. The outer container 5B is a modification of the outer container 5A. A receiving recess 53 extending downward from the upper end part of each of a pair of opposing sides of the outer cylindrical part 51 is formed in the above-mentioned upper end part. The receiving recess 53 includes a straight groove part 53 a and a circular hole part 53 b. The straight groove part 53 a is arranged at the central part of the upper end face of the outer cylindrical part 51. The straight groove part 53 a extends downward from the upper end face of the outer cylindrical part 51 with a constant width. The width of the straight groove part 53 a is set to be slightly smaller than the outside diameter of a shaft part 23 a of an engagement part 23 of the container C. Therefore, it is practically impossible to insert the shaft part 23 a downward into the straight groove part 53 a through the upper end opening part as long as the straight groove part 53 a of the outer cylindrical 51 is in a natural state with no external force is acted on the upper end part of the side of the external cylindrical part 51 in which the straight groove part 53 a is formed. However, by applying an external force to that particular side of the external cylindrical part 51 and spreading the width of the straight groove part 53 a, the shaft part 23 a can be inserted into the straight groove part 53 a through the upper end opening part. The circular hole part 53 b is arranged such that its axis passes through the center of the outer container 5B and its axis is aligned with the axis of the circular hole part 53 b which is formed in the other of the pair of sides. An upper side part of the circular hole part 53 b is in communication with a lower end part of the straight groove part 53 a. The inside diameter of the circular hole part 53 b is set to be generally equal to the outside diameter of the shaft part 23 a of the container C.

The container C is inserted in the outer container B through its upper end opening part. A flange part 21 of the container C is placed on an upper end face of the outer container 5B. The shaft part 23 a is fitted into the circular hole part 53 b through the straight groove part 53 a. By this, the outer container 5B and the container C are integrated.

FIG. 16 shows a fifth embodiment of a double container according to the present invention. In a double container K of this embodiment, the container D shown in FIG. 4 is used as an inner container, and a part of a reinforcement part 2 of the container D at a lower side of a flange part 21 of the reinforcement part 2 is tightly fitted to the upper end part inner peripheral surface of the outer container 5B over its entire periphery with almost no gap left therebetween. All the remaining construction is same as the above-mentioned double container J.

FIG. 17 shows a sixth embodiment of a double container according to the present invention. In a double container L of this embodiment, the outer container 5C is used as an outer container and the container A shown in FIG. 1 is used as an inner container. The outer container 5C is open not only at its upper end but also at its lower end, and it does not have a bottom part. The height of the outer container 5C is set to be larger than the distance between a lower surface of a flange part 21 of the container A and a lower surface of a container main body 1. Therefore, when the flange part 21 of the container A is placed on the upper end face of the outer container C, the bottom part 12 of the container main body 1 is located at the upper side of the lower surface of the outer container 5C.

FIG. 18 shows a seventh embodiment of a double container according to the present invention. In a double container M of this embodiment, the outer container 5D is used as an outer container and the container C shown in FIG. 3 is used as an inner container. In this outer container 5D, a receiving recess 53 having a straight groove part 53 a and a circular hole part 53 b is formed in one side part and the other side part of the upper end part of the outer container 5C. Therefore, in this container C, when the flange part 21 is placed on the upper surface of the outer container 5D, a shaft part 23 a of an engagement part 23 is fitted into the circular hole part 53 d through the straight groove part 53 a. 

1. A liquid container comprising a bottomed cylindrical container main body having a bottom part at a lower end part thereof and opening at an upper end thereof, and an annular reinforcement part disposed at an upper end part of said container main body, said container main body being entirely formed of a flexible thin film-like member, and said reinforcement part having strength enough to retain a constant shape in section.
 2. A liquid container according to claim 1, wherein said reinforcement part has a protrusion formed on an outer peripheral surface thereof and protruding radially outward with respect to an outer periphery of said container main body.
 3. A liquid container according to claim 2, wherein said protrusion is disposed at an upper end part of an outer peripheral surface of said reinforcement member.
 4. A liquid container according to claim 2, wherein said protrusion is annularly formed on said reinforcement part over an entire periphery thereof.
 5. A liquid container according to claim 4, wherein said protrusion is disposed on an upper end part of an outer peripheral surface of said reinforcement part.
 6. A liquid container according to claim 1, wherein said container main body and said reinforcement part are formed of a resin, and said reinforcement part is fused to an upper end part of said container main body.
 7. A liquid container according to claim 6, wherein said reinforcement part has a protrusion formed on an outer peripheral surface thereof and protruding radially outward with respect to an outer periphery of said container main body.
 8. A liquid container according to claim 7, wherein said protrusion is disposed at an upper end part of an outer peripheral surface of said reinforcement member.
 9. A liquid container according to claim 7, wherein said protrusion is annularly formed on said reinforcement part over an entire periphery thereof.
 10. A liquid container according to claim 9, wherein said protrusion is formed on an upper end part of an outer peripheral surface of said reinforcement part.
 11. A double container comprising a cylindrical outer container which is open at least at an upper end part thereof, and a bottomed cylindrical inner container having a bottom part at a lower end part thereof and opening at an upper end thereof, said inner container including a bottomed cylindrical container main body having a bottom part at a lower end part thereof and opening at an upper end thereof, and an annular reinforcement part disposed at an upper end part of said container main body, said container main body being entirely formed of a flexible thin film-like member, said reinforcement part having strength enough to retain a constant shape in section, and said reinforcement part having a protrusion formed on an outer peripheral surface thereof and protruding radially outward with respect to an outer periphery of said container main body, said inner container being inserted into said outer container through the upper end opening part of said outer container, and said protrusion being placed on an upper end face of said outer container.
 12. A double container according to claim 11, wherein said protrusion is disposed on an upper end part of an outer peripheral surface of said reinforcement part.
 13. A double container according to claim 11, wherein said protrusion is annularly formed on said reinforcement part over an entire periphery thereof.
 14. A double container according to claim 13, wherein said protrusion is disposed on an upper end part of an outer peripheral surface of said reinforcement part.
 15. A double container according to claim 11, wherein said container main body and said reinforcement part are formed of a resin, and said reinforcement part is fused to an upper end part of said container main body.
 16. A double container according to claim 15, wherein said protrusion is disposed on an upper end part of an outer peripheral surface of said reinforcement part.
 17. A double container according to claim 15, wherein said protrusion is annularly formed on said reinforcement part over an entire periphery thereof.
 18. A double container according to claim 17, wherein said protrusion is disposed on an upper end part of an outer peripheral surface of said reinforcement part. 